Magnesium and oxygen as in magnesium oxide
3. magnesium and sulfur
Among the elements listed, silicon is most likely to form covalent bonds. (Silicon is in the same periodic table column as carbon, which is the most likely of all atoms to form covalent bonds.)
what is the odd one lithium, nitrogen , oxygen , carbon
The lower mantle's chemical composition includes silicon, magnesium, and oxygen. Most likely, it probably also contains some iron, calcium, and aluminum The material at these depths is often referred to as the "post-perovskite" phase which is the high-pressure form of magnesium silicate (MgSiO3).
Silicon is most likely to form covalent bonds because it has four valence electrons and will share electrons rather than give them away.
3. magnesium and sulfur
On other planets, it will likely be carbon aswell, but silicon might be a possibility, since it has many of the same characteristics of carbon (being in the same column). The above is correct, but isn't quite emphatic enough. Silicon is probably the second best choice (the first choice being carbon), but it's at best an extremely distant second. Silicon binds too strongly with oxygen for silicon-silicon bonds to form to any substantial degree when there is oxygen present... and oxygen is the third most common element in the universe (after hydrogen and helium).
The most likely reaction is the formation of magnesium nitrate, carbon dioxide, and water.
Unless it is "deionized water" fresh water will contain dissolved minerals. Both magnesium and silicon are likely to be in those dissolved minerals, but I cannot state with certainty if a given water sample contains them unless it has been chemically analyzed.
Among the elements listed, silicon is most likely to form covalent bonds. (Silicon is in the same periodic table column as carbon, which is the most likely of all atoms to form covalent bonds.)
Silicon. Magnesium and sodium are metals and readily lose electrons to form cations, Mg2+ and Na+. Fluorine readily gains an electron to form the anion F-. Silicon on the otherhand in group 14 would need to gain 4 or lose 4 electrons to achieve the octet.
Silicon is very common in the universe and is shares almost all the qualities of carbon.
human cell.
Sodium
Organic Molecules are made up of two key elements, hydrogen and carbon. So the most likely answer to your question is any element that is not hydrogen of carbon. Maybe NaCi?
silicon like carbon is a non-metal. It is in group 14, and has a valency of 4. While the metallic nature of elemnts in a group increases as you go down the group only tin and lead are metals, silicon is a metalloid.
Helium.